The small disk of light visible in the back focal plane of an eyepiece. Related entry • exit pupil
Found on
http://www.daviddarling.info/encyclopedia/R/Ramsden_disk.html
<microscopy> The small circular patch of light that appears at the eyepoint above the ocular lens. This is the exit pupil of an optical instrument that, in a microscope adjusted for Koehler illumination, lies in a plane conjugate with the objective rear focal plane, condenser iris, and light source. Alteration of the Ramsden disk (for example...
Found on
http://www.encyclo.co.uk/local/20973
No exact match found.
